1. Field of the Invention
The present invention relates to a preamble of a wireless communication system. More particularly, the present invention relates to an apparatus and method for reducing a Peak to Average Power Ratio (PAPR) of a Secondary Advanced (SA) preamble for distinguishing a cell IDentifier (ID) in an Orthogonal Frequency Division Multiplexing (OFDM) wireless communication system.
2. Description of the Related Art
Many wireless communication technologies have been proposed as candidates to provide high speed mobile communication. Among these, the OFDM scheme is now recognized as a next-generation wireless communication technology. The OFDM scheme is a scheme of transmitting data using multiple carriers. However, in the case of using the OFDM scheme, there is a problem in that a transmit end has a high PAPR characteristic because it transmits one data stream through a plurality of subcarriers.
In the case of using the OFDM scheme, a Base Station (BS) transmits a synchronization channel for time synchronization and BS identification to a Mobile Station (MS). Here, the synchronization channel is called a preamble.
Through the synchronization channel received from the BS, the MS can acquire the time synchronization with the BS, and distinguish the BS to which the MS belongs. For example, the Institute of Electrical and Electronics Engineers (IEEE) 802.16m standard, which adopts the OFDM technology, makes use of a Primary Advanced (PA) preamble and an SA preamble. Here, the PA preamble is used for the time synchronization and the SA preamble is used for the BS identification.
In a case in which a BS transmits an SA preamble for time synchronization of the BS and BS identification as above, the BS converts a sequence constituting the preamble into an OFDM symbol and transmits the OFDM symbol. Thus, there is a problem that a PAPR of an SA preamble transmitted by the BS is high.